Refactor and rewrite to use yargs

[cmawhorter]

I put this together a while ago for my personal use and have been using it since without issue. Seems to work as well as it did before.

Summary of changes:

• Dropped getopt in favor of yargs
• Added editorconfig
• Added eslint
• Added .nvmrc for minimum supported version
• Restructured files a bit
• Created two entry points: cli and module
• Updated/removed unneeded deps

Edit: I added bunyan for my personal uses and then removed it for the pr.